Our current longitudinal study investigates the relation of early medical complications associated with prematurity to development through 24 mo in a large cohort of very low birth weight (VLBW) infants. In this competitive renewal application, assessments will be extended for the same group of infants to 36 and 48 mo of age. The ability of caretaking factors to facilitate or impede development in these children will continue to be evaluated. We will also investigate the relation of a group of maternal social and personal predictors to changes across time in the quality of mothers' parenting styles. The study will focus on the lower socioeconomic (SES) environment in which the increased likelihood of premature birth, combined with the developmental risks associated with negative social and parenting factors, place the infant at double jeopardy for poor outcome. The sample consists of 238 low SES, VLBW and 134 full term (FT) infants, matched for SES and maternal age. VLBW infants are subdivided into 2 risk groups (High risk = 100, Low risk = 138) according to the etiology and severity of their early medical complications. These complications ar all associated with central nervous system damage, which appears to result primarily from either focal brain lesion (e.g., intraventricular hemorrhage, periventricular leukomalacia) or from recurrent episodes of hypoxia secondary to respiratory disorders (e.g., respiratory distress syndrome, bronchopulmonary dysplasia). Specific medical complications are indexed so that their relation to infant development can be separately evaluated. The inclusion of a normal, FT group allows us to assess the degree to which infants of low or high medical risk differ in rates of development from infants with normal perinatal histories. The development of a broad range of skills and behaviors will be assessed at 6, 12, 24, 36 and 48 mo of age in conjunction with measures of maternal parenting styles and predictors of parenting. Our preliminary results at ages 6 and 12 mo show complex patterns of change in both infant and parent variables, and in their interactions, which differ significantly for the HR group. Examination of these differences at later timepoints will provide valuable information to help us design sensitive interventions which are timed and tailored to the unique developmental needs of HR infants, and also reflect the special needs and abilities of their low SES mothers.